CALIFORNIA, U.S. - On Monday, California created history, by becoming the sixth U.S. state to venture into legal sales of marijuana for recreational use.

Dozens of newly licensed stores catering to adults who enjoy the drug for its psychoactive effects opened for business up and down the state.

California became the most populous state by far, to venture beyond legalized medical marijuana to permit the sale of cannabis products of all types to customers at least 21 years old.

Recreational pot sales on a state-regulated licensed and taxed basis began in Colorado, Washington, Oregon, Alaska and Nevada first.

Later this year, Massachusetts and Maine will follow suit.

More than one-in-five Americans now live in states where recreational marijuana is legal for purchase.

However, overall under the U.S. law, cannabis remains classified as an illegal narcotic.

In California alone, the marijuana market boasts the world’s sixth-largest economy and is valued by most experts at several billion dollars annually.

The market is expected to generate at least a $1 billion a year in tax revenue.

Heather Azzi, a senior attorney for the Marijuana Policy Project, an advocacy group working to liberalize marijuana laws said in a statement, “Adding California to the regulated [recreational] market for cannabis is a really big deal.”

Most California jurisdictions are sitting out the highly anticipated New Year’s Day inauguration of recreational cannabis sales, since Los Angeles and San Francisco, will not be ready for days or weeks because of additional red tape required by city and county governments before would-be retailers can obtain their state licenses.

Business is however expected to see brisk sales at the newly permitted shops from Day One.

According to an authoritative guide to the cannabis market, GreenState, published by the San Francisco Chronicle, there are four-dozen outlets across California.

Stores authorized to carry recreational marijuana were set to go on New Year’s Day in San Diego, San Jose, Santa Cruz, Oakland, Berkeley, Eureka and Desert Hot Springs, among other locales.

Hundreds more are expected to open throughout the state as the year progresses.

According to reports, many that operated strictly as medical cannabis dispensaries under a patchwork of local regulations will now be licensed by the state for recreational merchandise as well.

Meanwhile, globally, Uruguay became the first and only country to legalize recreational marijuana sales nationally, through its pharmacies starting in July 2017.

The sale of the drug, however, is smaller in comparison, since the country boasts of a population of just 3.4 million.